By 2030, when the U.S. government or a company wants a new satellite in orbit, a robotic spider might build it in space.

Six- or eight-legged robotic spiders, capable of working with a 3D printer, gripping large objects and welding them together, are expected to build satellites or small spacecraft in the lower Earth orbit.

That means fewer spacecraft will be built on the ground, packed into a spacecraft and launched into space. Avoiding the stresses and expense of launch, the satellites will be less expensive, bigger and higher functioning.

"We're in early stages but we're making really good progress so far," said Rob Hoyt, CEO and chief scientist of Tethers Unlimited Inc., a Bothell, Wash.-based aerospace and defense research company. "If you want a satellite system with a large solar array or antenna, instead of fabricating the antenna on the ground and testing it to see if it could survive launch and still deploy reliably on orbit, we could use a robotic fabrication and assembly system and use additive fabrication techniques to build what you need in space. "

Dubbed SpiderFab, the project could changing the way spacecraft are built and deployed.

Today, satellites and other spacecraft are built on the ground, folded up and carefully packed into rockets that send them aloft. This process requires the satellites to be protected from the vibrations and G forces during liftoff. A significant portion of the engineering and launch costs of any space project are tied up in ensuring it survives liftoff.

Instead of launching entire spacecraft, engineers could send robots, barrels full of the metallic and plastic powders needed for additive manufacturing, 3D printers and the basic components needed to build a spacecraft. The prospect could means smaller, less expensive launch vehicles could be built , greatly reducing the cost of the craft's entire life cycle, according to NASA.

Tethers Unlimited is contracting with NASA to build a manufacturing platform that would work in space.

Hoyt hopes that 15 to 20 years from now there will be multiple platforms in different orbits around the Earth capable of building spacecraft that will then fall into that particular orbit.

Each platform would include a spider-like robot, or at least a robot with multiple arms, materials and at least one 3D printer.

"We're focusing our work now on figuring out how to, in space, make satellite components that are typically very large, like optics, solar arrays and antennas," Hoyt told Computerworld. "That's where on-orbit fabrication and assembly will have the best payoff … It's so expensive to design, build and test them so they can fold up to stow in a launch vehicle and then survive the tens of Gs of vibrations and shock during launch and then to deploy in the space environment.

"If you can fabricate them on orbit, you can launch the raw material in a much more compact form, and you can design them for the microgravity environment of space rather than the tens of Gs of launch," he said. "The combination of reduction in launch volume and mass, and the ability to make it bigger than you could possibly fold up into a rocket, means you can get an order of magnitude improvements of performance in cost."

Tethers Unlimited is focused on creating what's call a trusselator, a machine that takes spools of carbon fiber material and knits it together to build high-performance carbon fiber trusses, which can be used to build antennas or solar arrays.

So far, a prototype trusselator has been used to build a truss that was more than 52-feet long.

The 3D printers needed to build these large structures in space would look and function much differently.

"It isn't a typical 3D printer," Hoyt said. "The printers people use now are typically a big box that can make something smaller than that box. We want to have a tool that can make something much, much larger than itself. We're trying to figure out how to turn the 3D printer inside out. We need a tool that can act like a tiny spider building up a big web. And we have to figure out how to control the temperature of the materials while we're processing them -- and doing this in orbit where the temperatures vary by hundreds of degrees. That's a big challenge we need to address."

A big step for the company will be to test the manufacturing platform on the International Space Station in several years.